As recognized by the present inventors, in distributed storage systems there are instances where functions performed by a storage controller and associated with other components in the system may need to be migrated to other storage controllers in the distributed storage network. For instance, if a storage controller in the storage network fails, then the tasks and responsibilities associated with the failed storage controller need to be transferred or migrated to another storage controller in the network. Alternatively, if a particular storage controller is handling an excessive load, then it may be beneficial to distribute portions of the load to other storage controllers using migration, as recognized by the present inventors.
Accordingly, what is needed is a method and apparatus capable of migrating volumes and/or virtual disks from a first storage controller to one or more other storage controllers in a distributed storage network. In performing a migration, as recognized by the present inventors, it is desirable to perform such migration without interruption of data reads/writes that are in progress, such that the migration is transparent to the end user or process accessing the data stored in the distributed storage network.
It is against this background that various embodiments of the present invention were developed.